The invention discloses a welding method for a structural piece, and relates to the technical field of welding processes. The welding method includes the steps that a bottom plate and at least three partition plates are provided; two partition plates are taken, a steel pipe is provided, the steel pipe is arranged in through holes of the two partition plates in an inserted manner, and a distance fixing tool used for ensuring that the two partition plates are parallel is positioned, assembled and welded between the two partition plates; the two partition plates are positioned, assembled and welded to the bottom plate, and tool box iron is positioned, assembled and welded to corresponding lateral sides of the two partition plates; the steel pipe is taken out, and the two partition plates are welded to the bottom plate; the steel pipe is arranged in through holes of the placed partition plates and the through holes of the partition plates which have been welded, and distance fixing tools are positioned, assembled and welded between the placed partition plates and the adjacent partition plates; the placed partition plates are positioned, assembled and welded to the bottom plate; the corresponding lateral sides of the placed partition plates and the adjacent partition plates are connected and fixed to the tool box iron through positioning, assembling and welding; the steel pipe is taken out, and the placed partition plates are welded to the bottom plate; and the steps mentioned above are repeatedly executed, and the rest of the partition plates are welded to the bottom plate.